Furnace



Mardi 1, 1932. H. A. BRASSERT ET AL 1,847,710

FURNACE Filed Oct. 9, 1929 3 Sheets-Sheet l March l, 1932- H. A.BRAssERT ET AL 1,847,710

FURNACE 3 Sheets-Sheet 2 Filed Oct. 9, 1929 March l, 1932. H. A.BRAssERT ET AL 1,847,710

` FURNACE Filed oct. 9, 1929 s sheets-sheet 3 y jg.

Patented Mar. l, 1932 UNITED STATES PATENT AOFFICEy HERMAN A RRAssERT,SELWYNR P. XINNEY, AND HARRY I). WR'IHERBRR, or CHICAGO,

ILLINOIS, AssIGNoRs 'ro H. A. isRAssRR'r a COMPANY, oF CHICAGO,ILLINOIS, A

FUR-NACE Application led October 9, 1929. Serial No. 398,302.

This invention relates to ,a new and im.-

proved furnace of the vertical shaft type, and

more particularly to an improvement in the upper portion of furnaces ofthis character especiallyy adapted for use 'as blast furnaces for theproduction of pig iron. p v

During the past twenty years the trend of `blast furnace design has beenmore and more to increase "the diameter of the hearth of the furnace andat the same time to steepen the bosh angle and lower the height of thebosh. The result has beenthat blastfurnaces today are much'larger at thebottom than at the top. It will readilyy be seen that when the optimumwind is blown to'correspond to this greater increase'in hearthvarea,`that the'velocity of the gases at the top of the furnace is verygreat, and in some cases twice of what it used to be when the furnacehearthl was not materially larger than 'the top area, and consequentlyonly a half of the Wind volume blown. The difculty in regard toincreasing the topl dimensions tocorres'pond with the increased hearthdimensions has been that it isnot possible to obtaingo'odJ distributionwhen discharging the raw materials from .a large bell into the furnace,unless the-distance between the large bell and thefurnace wall is keptwithin comparatively narrow limits. 'Itis also not desirable to use toolarge a bell because with a larger bell the depression of the stockbelow the bell becomes too pronounced, resulting in the coarse materialsrolling into this depression and causing irregularity in thedistribution of coarse and fines, and in turn a very` porous'colum-n inthe center of the shaft. v

We propose to overcome these ditliculties by`laring out the -linesof theblast furnace at the top. In this way we are able to maintain the mostdesirable batter ofthe furnace inwall, which is required in order tohave a free working furnace and yet to have a stock line area of suchproportions that the velocity of the gases at the top is veryconsiderably reduced. Al/Ve have ascertained that within the layers ofmaterial nearest to the top, called stock line, the pressure drop pervertical foot lof stock drops faster than in the sections bev low,indicating a greater resistance to gas flow in the uppermost area. Bywideninvr out the top section this resistance is decreased and the speedof the flow of the gases. is reduced. Furthermore, with this design alarger size Ibell can beused without detriment, as thein- ,.vertedbatter will cause the materials to close in toward the center, therebytending to fill up the depression under the big bell. This rearrangementof materials will cause a cross mixing of the materials deposited nextto the wall with those which will have rolled' into\ the center. Afurther advantage of the reduced speed of the gases near the top of thefurnace is that less flue dust will be produced in this section and thatflue dust which has been generated Vin lower sections will tend todeposit in the -u pper section, thereby. greatly reducing the amount offlue dust produced. The cross mixing of the stock will afford abetter'contact between the gases and the solids, and Will result in asaving` of fuel, the advantage' of which is self-evident. `Theimportance of reducing ilue dust losses is equally" evident and is amatter of increasing importance with the In both cases the length oftimeof contact between gases and` solids is increased.' If this is doneby increased height, therblast .pressure is inc eased, resulting inagreat expenditure for powerY in blowing and more p ing the furnacehigherforby making it wider.

costly construction of the furnaceand wastage lgf energy yin hoistingthe materials to the top. Furthermore, with an increased velocity .ofgases through the furnace by means of an increased'height'of the descentof the charges the abrasion withinthe furnace is increased. The coke ispartially destroyed by a reductionof size before it reaches the hearth,resulting in the well known diilicul'- ties of operation..

With our type of furnace the same factor v of time is secured with adecrease in 'pressure, a-decrease 1n height of stock column,

.with a decreased tendency of-channeling which is generally caused by.too hi'gh a velocity in certain sections of the column.

Another advantage we claim for our invention is that the inverted batterin the top will protect the stock line due to the fact that the st'ockwill 'lie close -to the wall, the fines protecting the lining againstabrasion and the stock line armament, which enerally consists of castiron or steel mer-n ers embedded in the brick work, will not be s o aptto fallout due to undercutting of. the

. brick work. Furthermore7 with .our designof furnacethe'hightemperature gases will this upper portion of the brick work tothe'4 3.5 metal shell so that stresses occurring in both the brick .workandshell are minimized and the brick work is .held in placeagainst the Yshell.

We have also provided a construction '1 0 wherein the brick work in theuppermost portion of the furnace may be supportedby the shellindependently of the brick wor in the main body of the furnace. Thisuppermostbrick work is thereby not affected' b 4Iany vertical movementof the --main bric work. It is an object ofv the presentfinvention toprovide a new and` improved vertical shaft "furnace andmore particularlyto provide a 5{"'n'ew and improved upper construction for such afurnace. j It is. an additional object to provide a furnace whereinthequantity of flueodust produced and carried off from the furnace isreducedv and' wherein the gas velocities in the uppermost/portion yofthe furnace are rel duced. v

.It is a further object to provide a construction in which the materialscharged to 5 0 thefurnace are more uniformlydistributed throughoift thefurnace area than in customary furnace construction, and in which 'abetter distribution is had of the ascending gases among the descendinmaterials. It is also an object to provi e a construc- 'bodiments of ourinvention in the accomline -5-'5y of Figure 4 and 'and a substantiallycylindrical shaft portion 'most portion of the furnace is supported bvthe shell independently of the lower brick Other and furtherobjects-will appear as the description. proceeds.

We have illustrated certain'preferred empanying drawings, in Which-Figures -1, 2'and 3 are somewhat dia rammatic showings of differentforms o furnaces; Y.

Figure 4 is a section on an enlarged scale of the upper portion of thefurnace constructedaccording to our invention; Figurev 5 is afragmentary section taken on shown on an enlarged scale; and

Figure 6 is a fragmentary vertical section of part of Figure-4 on anenlarged scale.

Referring irst to the forms o ffconstruction shown in Figures 1, 2-and3, in Figure 1 a furnace is' outlined having a hearth portion 11, anoutwardly flaring bosh portion `12,

van inwardly inclined f-rusto-conical shaft portion 13, and anoutwardlyflaring uppermost portion '14. The portion 14 is shown as rounded andthe junction at 15 between the portions 13 and 14 is also rounded. The10 charging bell is shown at 16. In Figure 2 a furnace is vshown havinga hearth portion 17, a Haring bosh=portion 18,

19. The uppermost portion 20 inclines out- 105 .wardly and isin the formof an inverted frustrum of a cone. The portion20 joinszthe portion 19 online 21. The charging bell is v shown-at 22.A f f The form ofconstruction shown in Fignre 3 is generally similar to that shown inFigure-1 and comprises a cylindrical hearth portion( 23, Haring boshportion 24, inwardly inclined shaft portion 25 formedas the frustrum of'a cone, and a topmost portion 26 11,5

1 formed as an inverted frustrum of 'a cone and meeting the portion 25on .'l-ine 27. The charging bell is shown at28.

In Figure 4 we have shown more in detail aform ofconstruction similar tothat shown 12 in Figure 1. Here the metal kfurnace shell 29 is providedwith a brick lining 30 and 'with the stock linevpro'tecting` plates 31.'These plates 31 are located at the line of junction between the shaftportion of th'e furnace and the outwardly Haring portion 32, andare tiedinto the shell 29 by connecting plates The olftake passages 34 serve tocarry the products of combustion and blast gases vto the downcomers. Thelower charging bell 35 o 'may be operated .by any usual bell operatingmechanism and is 'shown as engaging the lower hopper section 36.

The details of construction of the bricky work and stock line protectionplates are4 shown in Figures 5 and 6. The brick lining 130 is shownas-provided with a series of plates .extending portions40 bonding themto the brick work and having the T-shaped heads 41 which protect thefaces of the brick work Aimmediately below the stock line. protectionplates 31.. These plates 31 have extensions 42 which are located behindthe T-heads 41 of g the pilates 39 and serve to hold thelower edges ofthe plates 31 in place.

The upper edges of the plates 31 have inwardly extending portions 43 andvertically extending portions 44, these latter engaging back of thevertically extending po tions 45 of the connecting plates 33. As bfstshown in the horizontal section of Figure ,the connecting plates 33 areprovided wit the extensions 46 which-engage behind the T-heads 47 of therails or tracks 48. These rails or tracks 48 are secured tothe innersurface of the metal shell 29.

It will be noted that the upper portion 49 of the metallic shell 29extends upwardly inside the furnace, the upper portion of which isenclosed by the upwardly flaring shell section 50. The topmost portion;51 of the main brick work in the furnace is located inside of the shellextension` 49.l The brick work 32 in the uppermost portion of thefurnace is thus supported by the plates 49 and 50 independently of themain body of the brick work in the furnace. Therefore any vertical eX-'pansion or contraction of the main brick work will not affect theuppermost brick work 32. It will valso be apparent that due to thesliding connection between the plates 33 and the T-sliaped rails48substantially no stresses are set up in the shell and there is noruptur? ing of the brick work when the brick work moves under expansionand contraction.

There are no holes or openings in the brick work necessary, as is thecase where usual v types -of tie rods or bars are used to hold the.

brick lining back against theI metal shell. The stock line protectionplates are effectively tied into the brick work and will not becomeloosened and fall out upon the impact of the incoming material. It willbeap- 'parent from a consideration of Figure 4 that the incomingmaterial will strike the inwardly sloping surfaces of the upperportionof the furnace and will be directed inwardly toward the center of thefurnace. This will serve to reduce the usual depression below thebelland will more uniformly mix the various sizes of material throughout thecross sectional'area of the furnace.

While we .have shown certain preferred embodiments vof our inventionjbyway of example, it is capable of change and modification to meet varyingconditions'and requirements,'land'wev contemplate buch Variations andchanges as come within the spirit and scope of-the appended claims.

' We claim:

1. In a vertical shaft furnace, an intermediate portion and an upperportion, brick work lining the intermediate sect-ion and brick Worklining the upper portion, the brick work of the upper portion beingsupported independently of the brick work in the intermediate portion. A

necting the shell and lining, said means hav-'1 ing a sliding connectionwith the shell.

4. In a vertical shaft furnace, a metal shell, a brick lining for theshell, and means connecting the shell and lining,-said means comprisingvertically extending T-shaped members secured to Athe Shell and memberscar- 'ried by the brick work and slidably engaging the T-sha ed members.

5. In a last furnace, a metal shell, a brick lining, an upper outwardlyflared portion ofthe brick lining located at the stock line,

- 2. In a vertical shaft furnace, a metallic shell, an intermediateportion and an upper and means slidably connecting the brick work to theshell at the stock line.

6. In a blast furnace, a metal shell, a brick lining, an upper outwardlyflared portion of the brick lining located] at the stock line, and meansslidably connecting the brick work to the shell at the stock line, saidmeans including stock line protection plates on the inner surface of thebrick and means slidably connecting @aid plate to the shell.`

7. In a blast furnace, a metal shell, a brick lining, metal stock lineplates fitted upon said brick lining, and means slidably connecting saidplates to the shell. V

8. In a blast furnace, a metal shell, a brick lining, metal stock lineplates fitted upon said brick lining, and means slidably ponnecting theplates to the shell, said means including vertically extending traclgmembers and members extending through the lining conv nect'ed to theplates and slidably engaging the tracks. f

9. In a blast furnace, a metal shell, a bric means slidably connectingthe connecting plates to the shell. f Y Y 10. jIn a blast furnace, ametal shell, a brick li/ning, stock line plates fitted in the i bricklininVr at the stock line, said plates hav- 'ng inwardly and verticallyextending portions, connecting plates having verticallyA extendingportionsengaging'the vertically extending portions of the stock lineplates, `verlo tically extending T-shaped tracks secured to the innersurface of the shell, and portions formed on the connecting platesextending behind the heads of the T-shaped tracks to slidably connectthe connecting plates and 15 stock line plates to the shell. i

11.4 In a blast furnace, a furnace shaft havan upper portion extendingbelow and above the stock line and flaring outwardly Y whereby the upperportionof the stock has a greater gas releasing area than a lowerportion ofthe stock whereby .gas velocity is reducedat the upper stocksurface and gas olftakes in communication with the entire upper surfaceof the stock. 12. In a blast furnace, a furnace shafthaving wallssloping upwardly and inwardly and an upper'wall portion Haring upwardlyand outwardly, 'the junction of the two portions being located below thestock line, a curved portion at the junction whereby the interior of theupper portion of the furnace is of generally Venturi section and gasoftakes in communication with the entire upper surface of the stock.

13. In a blast furnace, a shaft having walls sloping inwardly andupwardly and an upper section sloping outwardlyand upwardly, the planeof junction 'of the oppositely sloping walls containing a lesser furnaceinterior cross section than lplanes thereabove, said plane of junctionbeing located below the stock line, and a. bell rcarried by the furnacetop at a point materially above the plane of minimum charge materialdirectly against the upper outwardly flaring walls whereby thematerialis directed by said walls inwardly and f downwardly lto reduce the stockdepression `below the bell.

1f In a blast furnace, a shaft having walls sloping inwardly andupwardly and an up-v per section sloping outwardly and upwardly,

the plane of junction of the oppositely sloping walls containing alesser furnace interior cross section than planes thereabove, said planeo'f junction being located below the stock line, a bell carried by thefurnace top at a point materially above the plane of minimum furnacearea and sloped to discharge materialY directly against the upperoutwardly. flaring walls whereby the material is directed by said wallsinwardly and down- Y wardly to reduce the stock depression below thebell and gas oftakes connected to the upper' portion of the furnace andcommunifurnace area and sloped to 'dis-v eating with the space above theentire upper stock surface. Y

15. In a blast furnace, a shaft having walls sloping inwardly and`upwardlyand an upper section sloping outwardly and upwardly, the planeof junction of the oppositely sloping walls containing a lesser furnaceinterior cross section than planes thereabove, said l.

plane vofjunction being located below the stock line, and a bell carriedby the furnace topat such a height above the stock line4 and so slopedas to discharge material directly against the upper outwardly Haringwalls which causes the materials to lie closely'

